tACS for Aphasia

Overseen By Denise Harvey, PhD

Age: 18+

Sex: Any

Trial Phase: Academic

Sponsor: University of Pennsylvania

Disqualifiers: Neurological disorders, Psychiatric disorders, Alcohol/drug abuse, others

Compensation: Varies

Number of Visits: 1

Duration: 1 session

120 Participants Needed

Trial Summary

Will I have to stop taking my current medications?

The trial information does not specify whether you need to stop taking your current medications. However, if you have a history of significant or poorly controlled psychiatric disorders or current abuse of alcohol or drugs, you may not be eligible to participate.

What data supports the effectiveness of the treatment tACS for aphasia?

Research on a similar treatment, transcranial direct current stimulation (tDCS), suggests it can help improve language skills in people with aphasia (a language disorder) after a stroke. This is because tDCS can increase brain activity in areas important for language, potentially enhancing the effects of speech therapy. ^{1 2 3 4 5}

Is tACS safe for humans?

The research articles provided focus on tDCS, a similar non-invasive brain stimulation technique, which is generally considered safe for humans. However, specific safety data for tACS is not mentioned in these articles. ^{5 6 7 8 9}

How is the treatment tACS for aphasia different from other treatments?

Transcranial Alternating Current Stimulation (tACS) is unique because it uses alternating electrical currents to stimulate the brain, which may help improve language abilities in people with aphasia. Unlike other treatments like tDCS, which uses direct current, tACS may offer a different way to enhance brain plasticity and support language recovery. ^{2 5 8 10 11}

What is the purpose of this trial?

The goal of this study is to see if transcranial alternating current stimulation (tACS) can be used to enhance language abilities in people with post-stroke aphasia. Participants will receive real and sham tACS in conjunction with various language tests. Researchers will compare the post-stroke aphasia group with aged matched controls to see if brain response to tACS differs between groups.

Eligibility Criteria

This trial is for right-handed individuals who have had a stroke in the left hemisphere of their brain at least 6 months ago and are now experiencing aphasia, which affects language abilities. They must understand the study and agree to participate.

Inclusion Criteria

Must be able to understand the nature of the study, and give informed consent

My stroke happened more than 6 months ago.

I have difficulty with speaking or understanding language.

Timeline

Screening

Participants are screened for eligibility to participate in the trial

2-4 weeks

Treatment

Participants receive real and sham transcranial alternating current stimulation (tACS) in conjunction with language tests

1 session

1 visit (in-person)

Follow-up

Participants are monitored for language performance improvement and brain response to tACS

5-10 minutes after treatment

Treatment Details

Interventions

• tACS

Trial Overview Researchers are testing if active transcranial alternating current stimulation (tACS) can improve language skills in people with post-stroke aphasia. Participants will undergo real and sham tACS while performing language tests to measure effectiveness.

Participant Groups

Group I: real-tACS Active Control 1 Intervention

The active stimulation will consist of an alternating current delivered in the alpha frequency band with a peak-to-peak intensity of 4 milliamps (mA) for 20 minutes. Participants will complete sentence completion and verb generation task during stimulation.

Group II: sham-tACS Placebo Group 1 Intervention

Sham stimulation involves the delivery of 60 seconds of the actual stimulation waveform ("ramp up") which is then gradually reduced to 0 milliamps (mA) ("ramp down"). Participants will complete sentence completion and verb generation task during stimulation.

Who Is Running the Clinical Trial?

University of Pennsylvania

Lead Sponsor

Trials

2,118

Recruited

45,270,000+

Findings from Research

In a study of 37 stroke patients, speech therapy combined with transcranial direct current stimulation (tDCS) significantly improved language function, with an average increase in aphasia quotient (AQ%) of 14.94% after treatment.

Patients with less severe, fluent types of aphasia who started treatment within 30 days of their stroke showed the best responses, and those with hemorrhagic strokes had a higher likelihood of improvement compared to those with infarctions.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

The Factors Associated with Good Responses to Speech Therapy Combined with Transcranial Direct Current Stimulation in Post-stroke Aphasic Patients. Jung, IY., Lim, JY., Kang, EK., et al.[2021]

In a study of 58 right-handed English speakers with subacute aphasia, transcranial direct-current stimulation (tDCS) did not significantly enhance picture naming accuracy compared to sham treatment, indicating limited efficacy for this specific outcome.

However, tDCS was associated with greater improvements in discourse skills, which are important for communication, and no adverse events were reported, suggesting it is a safe adjunct to language therapy.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Transcranial Direct-Current Stimulation in Subacute Aphasia: A Randomized Controlled Trial. Stockbridge, MD., Elm, J., Breining, BL., et al.[2023]

In a study involving 37 participants with moderate to severe aphasia, repeated anodal transcranial direct current stimulation (A-tDCS) did not show a significant positive impact on language recovery when combined with language therapy, compared to a sham stimulation group.

Both groups showed improvement in language abilities after therapy, but there were no statistically significant differences in outcomes between the A-tDCS and control groups, indicating that A-tDCS may not provide functional benefits in early post-stroke rehabilitation for aphasia.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

No effects of anodal transcranial direct stimulation on language abilities in early rehabilitation of post-stroke aphasic patients. Polanowska, KE., Leśniak, M., Seniów, JB., et al.[2019]

In a study involving 11 chronic stroke patients with aphasia, dual transcranial direct current stimulation (tDCS) showed a significant improvement in naming response times compared to baseline, suggesting enhanced efficacy over single tDCS.

Both single and dual tDCS improved the number of correct responses in naming tasks, but dual tDCS, which targeted both the left and right inferior frontal gyri, may offer greater benefits for language recovery in stroke patients.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Effects of dual transcranial direct current stimulation for aphasia in chronic stroke patients. Lee, SY., Cheon, HJ., Yoon, KJ., et al.[2021]

Transcranial direct current stimulation (tDCS) combined with language training showed improved verb production in a 43-year-old male with fluent-anomic aphasia after a stroke, suggesting enhanced language recovery.

The study indicates that using tDCS over Broca's area during language therapy may effectively support brain plasticity and improve language skills in individuals with aphasia.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Translational treatment of aphasia combining neuromodulation and behavioral intervention for lexical retrieval: implications from a single case study. Galletta, EE., Vogel-Eyny, A.[2020]

In a study involving 10 individuals undergoing standard aphasia therapy, 70% expressed interest in and were eligible for transcranial direct current stimulation (tDCS), which was administered during therapy sessions.

Data from four participants showed a large effect size (Cohen's d = 1.32) favoring active tDCS over sham stimulation, suggesting that tDCS may enhance communication outcomes in aphasia therapy, although one participant with severe deficits did not benefit.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Clinical Feasibility of Combining Transcranial Direct Current Stimulation with Standard Aphasia Therapy. Duncan, ES., Nakkawita, SG.[2022]

A systematic review of 25 studies involving 471 participants found that Transcranial Direct Current Stimulation (tDCS) did not improve overall functional communication in stroke patients, indicating limited efficacy for this primary outcome.

However, anodal tDCS, especially when applied over the left inferior frontal gyrus, showed a significant improvement in noun naming performance, suggesting it may be a promising targeted treatment for specific language deficits after stroke.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Transcranial direct current stimulation (tDCS) for improving aphasia after stroke: a systematic review with network meta-analysis of randomized controlled trials. Elsner, B., Kugler, J., Mehrholz, J.[2020]

Transcranial direct-current stimulation (tDCS) significantly improved articulatory accuracy in patients with aphasia after stroke, indicating its potential effectiveness in enhancing speech production.

While tDCS showed qualitative improvements in naming and syllable repetition tasks, these results were not statistically significant, suggesting that further research is needed to fully understand its impact.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Effect of Anodal tDCS on Articulatory Accuracy, Word Production, and Syllable Repetition in Subjects with Aphasia: A Crossover, Double-Blinded, Sham-Controlled Trial. Vila-Nova, C., Lucena, PH., Lucena, R., et al.[2021]

A systematic review of five trials with 54 participants found no evidence that transcranial direct current stimulation (tDCS) improves speech and language therapy outcomes for stroke patients with aphasia.

While no adverse events were reported, the studies primarily measured picture naming rather than real-life communication, and cathodal tDCS over the non-lesioned hemisphere showed potential as a promising approach.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Transcranial direct current stimulation (tDCS) for improving aphasia in patients after stroke. Elsner, B., Kugler, J., Pohl, M., et al.[2022]

Transcranial direct current stimulation (tDCS) applied to the left inferior frontal gyrus significantly improved language abilities in patients with nonfluent poststroke aphasia when combined with speech language therapy, as shown by a higher Aphasia Quotient in the A-tDCS group compared to the sham group (72.99 vs. 46.18).

The study involved 18 patients over four weeks, with results indicating that tDCS enhances the effectiveness of speech language therapy, particularly in areas other than comprehension, suggesting a beneficial mechanism of action for language recovery.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Effect of Anodic Transcranial Direct Current Stimulation Combined With Speech Language Therapy on Nonfluent Poststroke Aphasia. Zhao, Q., Wang, J., Li, Z., et al.[2022]

In a study involving eight patients with aphasia, bihemispheric transcranial direct current stimulation (tDCS) combined with intensive language therapy led to significant improvements in language tasks, including articulation accuracy and speed, after just 10 days of treatment.

The positive effects of this bihemispheric stimulation persisted even one week after treatment, suggesting that this method may enhance recovery in chronic aphasia patients more effectively than previous unihemispheric approaches.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Bihemispheric stimulation over left and right inferior frontal region enhances recovery from apraxia of speech in chronic aphasia. Marangolo, P., Fiori, V., Cipollari, S., et al.[2013]

References

1. Korea (South) pubmed.ncbi.nlm.nih.gov

The Factors Associated with Good Responses to Speech Therapy Combined with Transcranial Direct Current Stimulation in Post-stroke Aphasic Patients. [2021]

2. United States pubmed.ncbi.nlm.nih.gov

Transcranial Direct-Current Stimulation in Subacute Aphasia: A Randomized Controlled Trial. [2023]

3. Poland pubmed.ncbi.nlm.nih.gov

No effects of anodal transcranial direct stimulation on language abilities in early rehabilitation of post-stroke aphasic patients. [2019]

4. Korea (South) pubmed.ncbi.nlm.nih.gov

Effects of dual transcranial direct current stimulation for aphasia in chronic stroke patients. [2021]

5. Switzerland pubmed.ncbi.nlm.nih.gov

Translational treatment of aphasia combining neuromodulation and behavioral intervention for lexical retrieval: implications from a single case study. [2020]

6. India pubmed.ncbi.nlm.nih.gov

Clinical Feasibility of Combining Transcranial Direct Current Stimulation with Standard Aphasia Therapy. [2022]

7. England pubmed.ncbi.nlm.nih.gov

Transcranial direct current stimulation (tDCS) for improving aphasia after stroke: a systematic review with network meta-analysis of randomized controlled trials. [2020]

8. New Zealand pubmed.ncbi.nlm.nih.gov

Effect of Anodal tDCS on Articulatory Accuracy, Word Production, and Syllable Repetition in Subjects with Aphasia: A Crossover, Double-Blinded, Sham-Controlled Trial. [2021]

9. England pubmed.ncbi.nlm.nih.gov

Transcranial direct current stimulation (tDCS) for improving aphasia in patients after stroke. [2022]

10. United States pubmed.ncbi.nlm.nih.gov

Effect of Anodic Transcranial Direct Current Stimulation Combined With Speech Language Therapy on Nonfluent Poststroke Aphasia. [2022]

11. France pubmed.ncbi.nlm.nih.gov

Bihemispheric stimulation over left and right inferior frontal region enhances recovery from apraxia of speech in chronic aphasia. [2013]